info.ephyra.search.searchers
Class KnowledgeAnnotator

java.lang.Object
  java.lang.Thread
      info.ephyra.search.searchers.Searcher
          info.ephyra.search.searchers.KnowledgeAnnotator

All Implemented Interfaces:

java.lang.Runnable

Direct Known Subclasses:

WikipediaKA, WorldFactbookKA

public abstract class KnowledgeAnnotator
extends Searcher

A KnowledgeAnnotator searches a (semi)structured knowledge source. It provides a specialized solution to certain classes of questions, described by a set of question patterns. Only questions that match at least one of the patterns in the field qPatterns are supported by a KnowledgeAnnotator.

It runs as a separate thread, so several queries can be performed in parallel.

This class extends the class Searcher and is abstract.

Version:

2005-09-28

Author:

Nico Schlaefer

Nested Class Summary

Nested classes/interfaces inherited from class java.lang.Thread

java.lang.Thread.State, java.lang.Thread.UncaughtExceptionHandler

Field Summary

protected int	index Index of the matching pattern.
protected java.util.regex.Matcher	matcher The Matcher that matched the pattern with the question.
protected java.lang.String	name Name of the knowledge annotator.
protected java.util.ArrayList<java.lang.String>	qContents Strings identifying the relevant content of a question by referring to the groups in the corresponding question patterns.
protected java.util.ArrayList<java.util.regex.Pattern>	qPatterns A question that matches at least one of these patterns can be handled by the KnowledgeAnnotator.

Fields inherited from class info.ephyra.search.searchers.Searcher

query, results

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

	KnowledgeAnnotator(java.lang.String filename) Creates a KnowledgeAnnotator and reads the question patterns and descriptors of the relevant content of a question from a file.
protected	KnowledgeAnnotator(java.lang.String name, java.util.ArrayList<java.util.regex.Pattern> qPatterns, java.util.ArrayList<java.lang.String> qContents) Protected constructor used by the getCopy() method.

Method Summary

protected java.lang.String	getContent() Extracts the relevant content of a question by resolving the group identifiers of the format [group_no] in the content string that corresponds to the matching pattern.
abstract KnowledgeAnnotator	getCopy() Returns a new instance of the KnowledgeAnnotator.
java.lang.String	getKAName() Returns the name of the knowledgeAnnotator.
protected Result[]	getResult(java.lang.String answer, java.lang.String docID) Creates an array of a single Result object form an answer string and a document ID.
protected boolean	matches(Query query) Tests whether the knowledge annotator is appropriate for a question by applying the patterns in the field qPatterns.
boolean	start(Query query) Sets the query and starts the thread if the knowledge annotator is appropriate for the user question.

Methods inherited from class info.ephyra.search.searchers.Searcher

doSearch, run

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getAllStackTraces, getContextClassLoader, getDefaultUncaughtExceptionHandler, getId, getName, getPriority, getStackTrace, getState, getThreadGroup, getUncaughtExceptionHandler, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setDefaultUncaughtExceptionHandler, setName, setPriority, setUncaughtExceptionHandler, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

name

protected java.lang.String name

Name of the knowledge annotator.

qPatterns

protected java.util.ArrayList<java.util.regex.Pattern> qPatterns

A question that matches at least one of these patterns can be handled by the KnowledgeAnnotator.

qContents

protected java.util.ArrayList<java.lang.String> qContents

Strings identifying the relevant content of a question by referring to the groups in the corresponding question patterns.

index

protected int index

Index of the matching pattern.

matcher

protected java.util.regex.Matcher matcher

The Matcher that matched the pattern with the question.

Constructor Detail

KnowledgeAnnotator

protected KnowledgeAnnotator(java.lang.String name,
                             java.util.ArrayList<java.util.regex.Pattern> qPatterns,
                             java.util.ArrayList<java.lang.String> qContents)

Protected constructor used by the getCopy() method.

Parameters:

name - name of the KnowledgeAnnotator

qPatterns - question patterns

qContents - descriptors of the relevant content of a question

KnowledgeAnnotator

public KnowledgeAnnotator(java.lang.String filename)
                   throws java.io.IOException

Creates a KnowledgeAnnotator and reads the question patterns and descriptors of the relevant content of a question from a file.

The file must have the following format:

KnowledgeAnnotator::
[name of the knowledge annotator]

QuestionPatterns:
[regular expression 1]
[relevant content 1]
...
[regular expression n]
[relevant content n]

The relevant content of a question is described by a string that may contain group identifiers of the format [group_no] that are replaced by the capturing groups that occur in the corresponding question pattern.

Parameters:

filename - file containing the question patterns and descriptors of the relevant content of a question

Throws:

java.io.IOException

Method Detail

matches

protected boolean matches(Query query)

Tests whether the knowledge annotator is appropriate for a question by applying the patterns in the field qPatterns.

Parameters:

query - Query object

Returns:

true, iff the question matches at least one of the patterns in qPatterns

getContent

protected java.lang.String getContent()

Extracts the relevant content of a question by resolving the group identifiers of the format [group_no] in the content string that corresponds to the matching pattern.

Returns:

relevant content of the question

getResult

protected Result[] getResult(java.lang.String answer,
                             java.lang.String docID)

Creates an array of a single Result object form an answer string and a document ID.

Parameters:

answer - answer string

docID - document ID

Returns:

array of a single Result object

getKAName

public java.lang.String getKAName()

Returns the name of the knowledgeAnnotator.

Returns:

name of the knowledge annotator

getCopy

public abstract KnowledgeAnnotator getCopy()

Returns a new instance of the KnowledgeAnnotator. A new instance is created for each query.

It does not necessarily return an exact copy of the current instance.

Returns:

new instance of the KnowledgeAnnotator

start

public boolean start(Query query)

Sets the query and starts the thread if the knowledge annotator is appropriate for the user question.

This method should be used instead of the inherited start() method without arguments.

Parameters:

query - query object

Returns:

true, iff the knowledge annotator is appropriate and the thread was started